Biology subjects

Lundgren, J.

Publications and source records attributed to Lundgren, J..

3 recordsLinked to original sources

bioRxiv2024

Interactions between Brassica carinata and its pollinators is shaped by managed beehives and neonicotinoid seed treatment

Brassica carinata is a biofuel and animal feed crop with expanding global production. Although there is much research on common farming practices to improve yield, there is almost a complete absence of data on the dependency of yield through pollination services. Reciprocally, we lack information on whether B. carinata offers ecosystem services to pollinators. We observed almost 4000 pollinator visits, quantified different plant functional traits, including floral resources and examined the effect of supplementing fields with honey bee hives and the use of neonicotinoid seed treatment on seed yield and honey bee health. Data was collected from 35 0.404-ha sites with more than 800 focal B. carinata individuals across 2 years in the Prairie Coteau region of the Northern Great Plains. We found that pollinators (n = 28 species) are attracted to floral resources at different spatial scales. High visitation rates by pollinator species were associated with double the seed set in B. carinata relative to the lowest visitation rates. Brassica carinata adds floral resources to the agricultural ecosystem and therefore has the potential to increase pollinator health. However, species interactions are influenced by the use of insecticides and the presence of honey bees by managed beehives. In particular, insecticides alter the role of pollinators on crop pollination by reducing the positive impact of floral resources on pollinator-mediated yield and honey bee health.

ecology↗

bioRxiv2020

The effect of pasture management on fire ant, Solenopsis invicta (Hymenoptera: Formicidae), abundance and the relationship to arthropod community diversity

The red imported fire ant, Solenopsis invicta, is one of the most prolific invasive species to the Southeastern U.S. These invaders preferentially colonize highly disturbed land and grassland habitat. Management of livestock in pasture systems can have a profound impact on the level of disturbance in grassland habitats, and we hypothesized that pasture management would have a significant effect on S. invicta abundance in the Southeastern U.S., and arthropod diversity would negatively correlate with this invasive species. We studied the effects that pasture management systems (based on stocking density, rotation frequency, and insecticide application rates) have on fire ant mound abundance and arthropod diversity for the soil, foliar, and dung communities. S. invicta mounds were quantified and mound areas were documented along transect lines in six pastures. Soil and foliar arthropod communities were collected along the same transect lines, and dung communities sampled from pats within the pasture system. Pastures managed under adaptive multi-paddock (AMP) practices had 3.35x more S. invicta mounds and 4.64x more mound area than their conventionally managed counterparts. However, arthropod diversity did not correlate with S. invicta abundance for any of the three arthropod communities sampled. This study shows pasture management can have a significant impact on S. invicta mound abundance, but arthropod communities in AMP managed pastures did not suffer decreased diversity from increased abundance of S. invicta. Additionally, this study demonstrates that this invasive species does not necessarily contribute to diversity decline, at least under AMP pasture systems.

ecology↗

bioRxiv2019

Maximizing Ecosystem Services Provided To The New Oil Crop Brassica carinata Through Landscape And Arthropod Diversity

Prairies, once spanning the Upper Midwest, have now largely been replaced by agriculture. The lack of resources available to pollinators in agricultural fields and practices commonly employed has led to a decline in insect diversity. To enhance sustainable practices, we must better understand how ecosystem services such as pest control and pollination services provided by a diverse insect and pollinator community scale to current farming practices as related to crop yield and how landscape features may positively contribute to insect and pollinator diversity. We examined how landscape heterogeneity relates to insect and pollinator diversity, as well as how insect and pollinator diversity relates to crop yield across common farming practices. We planted 35 single acre sites of Brassica carinata, a generalist flower possibly capable of supporting a diverse insect community. We randomly assigned each site with a combination of three common farming practices: tilling (yes/no), added honey bee hives (yes/no), and treatment with systemic neonicotinoids (yes/no). Insect and pollinator diversity and the surrounding landscape at multiple spatial scales were calculated. We observed a significant positive relationship between insect (and pollinator) diversity with yield in the absence of any farming practice. All farming practices will increase yield. However, farming practices alter the relationship between yield and diversity. The addition of seed treatment or tillage negates the relationship between insect (and pollinator) diversity with yield. Seed treatment alone results in a flat relationship between diversity and yield for all insects and a negative relationship for pollinators. Increased landscape heterogeneity results in a positive relationship between insect diversity at the 1000 m scale and pollinator diversity at the 3000 m scale, suggesting large-scale heterogeneity contributes to overall insect diversity. Our results show that increasing large-scale landscape heterogeneity increases diversity serving as a substitute for common farming practices such as application of pesticides, tilling, or bee hives. Increased heterogeneity could save farmers from the input cost of treatment or tillage, by way of increased insect diversity, while still providing similar yields.

ecology↗